LIFE-HISTORY OF AMPHIGONOPTERUS AURORA. 



cently reviewed the family from a taxonomic standpoint (Hubbs, 

 1918), and have studied the life-history of several species, that 

 of Amphigonopterus aurora (Fig. 2) in greatest detail. Although 

 the following account is largely based on this species, comparisons 

 with others are made in several connections. 



ECOLOGY. 



Nothing whatever has been written concerning the life-history 

 of Amphigonopterus aurora, the only species of the genus, and all 

 that has been printed concerning its environmental relations is the 

 statement that it is an inhabitant of the tide-pools of Monterey 

 Bay, California, and that it feeds on algae. Its habit of feeding 



FIG. i. Adult female of Micrometnis minimus. 



on algae, except when very young, when I found it feeding on 

 copepods, is correlated with its tricuspid teeth and comparatively 

 elongate intestine. Similarly I found that the related Micro- 

 metnis minimus (Fig. i), though chiefly herbivorous, feeds on 

 small crustaceans when young (Pt. Loma ; December 31), and 

 occasionally is caught on clam bait when adult. These two species 

 alone comprise a distinct subfamily, the Micrometrinae, which I 

 have recently distinguished (Hubbs, 1918). 



Amphigonopterus aurora inhabits the tidal pools and channels 



